import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main3 {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        in.nextLine();
        String str = in.nextLine();
        int countS = 0;
        int countH = 0;
        int countY = 0;
        for(int i = 0; i < n; i++) {
            char ch = str.charAt(i);
            if(ch == 's') {
                countS++;
            }else if(ch == 'h') {
                countH++;
            }else if(ch == 'y') {
                countY++;
            }
        }
        int ret = countS * countH * countY;
        System.out.println(ret);
    }
}